<?php

$db = new PDO('mysql:host=localhost', 'root', '12qwas');
$r = $db->exec('create database if not exists db3');
$r = $db->exec('use db3');
$r = $db->exec('create table if not exists students(xh varchar(9) primary key, name varchar(50), age int default 0)');
$r = $db->exec("delete from students where xh='233110201'");
var_dump($r);
$db->exec('truncate table students');//删除表中的所有数据
$r = $db->exec("insert into students(xh,name,age) values('233110201','张三',18),('233110202','李四',20),('233110203','王五',19)");
var_dump($r);
$r = $db->exec("update students set name='张三丰' where xh='233110201'");
var_dump($r);